Combined switch and circuit breaker



Oct. 18, 1932. A. H. NERO COMBINED SWITCH AND CIRCUIT BREAKER Filed April 6. 1929 2 Sheets-Sheet INVENTOR ARV ID H. NERO m fills aZFor ey-s .,zo muz mmm 5650 :0 10:26

Oct. 18, 1932. .-A. H. NERO COMBINED SWITCH AND CIRCUIT BREAKER 2 Sheets-Sheet 2 Filed April 6. 1929 LLDUEU mmO IUPZSW INVENTOR I ARVID H.NERO 6;! his a Z'Zpr/aqy-S 8 \Q h il Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE 'ARVID H. NERO, OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO THE ARROW-HART & HEGEMAN ELECTRIC COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT COMBINED SWITCH AND CIRCUIT BREAKER Application filed April 6, 1929. Serial No. 353,166.

This invention relates to switches and more particularly to that type of switch which is provided with a bi-metallic thermal element through which current passes and which element upon the passage of excessive current therethrough, bends to break the electric circuit through the switch.

The invention has for an object the providing of a mechanical overload, circuit breaking means in series circuit with a tumbler snap switch. This object embraces the further object of eliminating the. safety fuses which have hitherto been used in circuit with switches in electric lighting and power systems. By use of the overload circuit breaker the fuses may be dispensed with.

Another object is to provide improved visible indicating means to inform people whether the'switch is in condition to pass current through it or not.

Another object is to provide indicating means showing the condition of operation of the device, which means will automatically operate upon circuit breaking, whether or not the operating handle of the switch remains stationary during such change.

Other objects will be apparent as my invention is described in connection with the accompanying drawings in which Fig. 1 is a side elevation view of a snap switch mechanism combined with a circuit breaker according to the principles of my invention. One side of the casing is removed to show the interior mechanism.

Fig. 2 is a side elevation view of the switch and circuit breaker shown in Fig. 1. A portion of the mechanism is broken away for the sake of clearness.

' Fig. 3 is a side elevation View of my invention similar to Fig. 2, but with the switch contacts in a different position.

Figs. 4, 5 and 6 are top plan views of my invention shown in Figs. 1, 2 and 3 with a portion of the face plate broken away and showing the mechanism in various positions.

Fig. 7 is a top plan View of my invention showing the casing with the face plate and switch mechanism removed.

Fig. 8 is an end elevation of a portion of the mechanism shown in Figs. 1 to 6 with the operating mechanism removed from the casmg.

Fig. 9 is a fragmentary detail View showing in section a portion of this mechanism of Fig. 8.

Referring to the drawings it will be noted that my invention is composed of a tumbler snap switch mechanism, the specific construction of which, per se, forms no part of the present invention except insofarv as it cooperates with the other parts of the invention as will now be described. My invention comprises, in combination with the snap switch, a circuit breaker which is spring biased to off (i. e. circuit breaking) position.

The circuit breaker is held on on (i. e. c1r cu1t completing) position by latch mech- 3111:8111 controlled by a bi-metallic thermal bar which, when overheated, as for example by excessive current passing therethrough, will bend and release the latch mechanism thus allowing the circuit breaker to open.

To reset thecircuit breaker, the switch, which remains in on position during the circuit opening operation of the circuit breaker, must be thrown to off position and then to complete the circuit through the device the switchmust be thrown to on position after the thermal bar has cooled. Appropriate mechanism is provided to accomplish the resetting and this mechanism will be described in detail in connection with the drawmgs.

The device is contained within an insulating casing 10 and is suspended Within said casing by a metallic strap 12 passing across the top of the casing and secured thereto by screws as is usual in tumbler type snap switches. As usual the switch is actuated by a hand lever 14 projecting from the casing through an aperture 16 located centrally in the strap. This lever is pivoted on a switch spindle 17 which is pivotally mounted in bearing holes in parallel side plates 18, 18 depending from the strap 12.adjacent the straps center portion. These plates 18, 18 may be and preferably are formed integral with the strap 12 and are caused to depend therefrom by bending the plates downwardly.

The hand lever has a resetting finger projectin 'from it between and parallel to the-side p ates. This finger cooperates with the trip mechanism of the circuit breaker as will be described presently. Since the snap switch mechanism forms no part of this invention it will not be described. It will be suflicient to say that any of the well known tumbler snap switch mechanisms may be employed to move the bridging contact member of the switch from a position of non-engagement with the stationary switch contacts 24, to a position where it does engage those contacts, as the operating lever 14 is oscillated.

The stationary switch contacts 24, 25 are placed to one side of the switch mechanism,

0th stationary contacts being located in the same plane as the movable contacts so that the movable contacts 26, 27 upon oscillation of the bridging member will engage and disengage the stationary contacts 24, 25.

The stationary switch contact 25 which is secured to the bottom of the casing, is connected by a conducting bar'29 to a stationary circuit breaker contact 30 also located in the bottom of the casing but on the opposite side of the switch mechanism. This circuit breaker contact 30 cooperates with one arm of a movable U-shaped bridging contact member 34 of the circuit breaker, upon which arm is a movable circuit breaker contact 32.

Another stationary circuit breaker contact 31 is provided adjacent an end wall of the casing 10 and this contact 31 cooperates with another movable circuit breaker contact 33, on the other arm of the bridging member 34. This contact is connected to a wire terminal 35 through the bi-metallic thermal U bar 36 which will be described hereinafter.

For the purpose of mounting the circuit breaker bridging contact member 34 I extend the spindle 17 beyond that side plate 18' of the strap which plate is away from the switch contacts. On this extension I place a sleeve 40 which has connected to "it at its inner end a bent arm 42, a portion of which is flat and exterids along parallel to the sleeve, but spaced from it. Upon this arm the-circuit breaker bridging contact 34 is insulatingly mounted. A wire spring 41 is wound around the sleeve 40 to bias the circuit breaker bridging contact in open or 011' position. One end of the spring is anchored to the side plate 18 while the other end presses against the flat arm 42.

To hold the circuit breaker closed and to allow it to fly open upon an overload occurring in the circuitthe following mechanism is rovided:

ecured to the inner end of the sleeve 40, so as to rotate with the sleeve and bridging contact 34, is a latch bar 44 having a finger 45 extending from its free end, which co- 47 downwardly extending to cooperate with the bi-metallic thermal element 36.

The thermal element 36 is made, as usual,

by welding upon each other, two U shaped strips of metal having different coefficientsof expansion. The legs 37, 38 of the element are pinned to a step 39 in the bottom of the casing leaving the U end of the element free to move up and down in the well known manner, as the temperature of the element changes. Current passes through the thermal element 36 from the binding terminal 35. When an excess current,passing through the element 36, heats it, it will respond by bending downwardl to disengage the trigger finger 47 and al ow the circuit breaker to fly open under the action of the spring 41.

Extending up from the trigger member 47 near its pivot is a curved arm 48 so placed as to move .in the plane of the latch bar 44 and to cooperate therewith. Near the pivot of the trigger member 47 there is a hollowed place 49 in the trigger arm 48 in which hollow the latch arm finger 45 may project and be held therein as the trigger finger 47 is tilted away from the thermal element 36 or is held against movement by that element.

In order to reset the circuit breaker when it has been tri Fped open, that is, moved to off position ig. 1 dotted position) by the spring 41, an arm 50 laterally extending from the end of the latch bar, projects into the path of movement of the resetting finger 20 as that finger moves between the side plates when the operating lever is oscillated.

Assuming the circuit breaker to be open and the switch closed as will be the normal relation of the parts after the circuit has been interrupted on overload, the resetting finger 20 will then be near the to and the latch bar arm 50 will he resting against the resetting finger 20. (Fig. 8.)

Actuation of the operating lever now will cause the resetting finger 20 to press the latch bar arm 50 down and thus move the circuit breaker bridging contact to on position, because the bridging contact is rigidly connected to the latch bar 44. During this movement the finger 45 on the end of the latch bar will have moved down the I curved surface of the trigger arm 46 and into the hollow 49 therein and have pressed against the side of that hollow tilting the trigger 47 away from the thermal bar. If

the thermal bar is cool it will snap up into the path of the trigger 47, preventing the trigger, for the present, from moving to release the circuitbreaker. v

Since the switch was on (Fig. 2) when the hand lever 14 was actuated, the actuation strap 12 of the hand lever moved the switch off (Fig. 3) at the same time that it reset the circuit breaker on (Figs. 3, 6). Thus actuation of the hand lever 14 again, will throw the switch on but will not move the circuit breaker (Figs. 2 and 4). By this last actuation the circuit is completed. This last actuation of the hand lever (turning switch on) moved the resetting finger 20 up to the strap (Fig. 2) and away from the latch arm 50 and therefore if the thermal element now becomes heated (dotted position Fig. 1) it will release the trigger 47 which will in turn release the latch bar 44 and allow the spring 41 to act to open the circuit breaker.

From the above it will be apparent that the switch may be opened and closed at will without ever tripping the circuit breaker since the circuit breaker tripping mechanism is entirely independent of the switch. However, when the switch is closed it automatically resets the ciircuit breaker if the circuit breaker happened to have been tripped prior to the switch opening.

As is customary with snap switches, I provide a rectangular face plate 70 to cover up theswitch mechanism. The hand lever projects through an aperture 71 in the plate as usual, but in order that people may know the condition of the circuit, a small window 72 is provided above the lever aperture. Through this window indicating means consisting of a plate 75 bearing the legends on and off is visible.

Mechanism is provided by which the off legend will be visible when either the switch or circuit breaker is open; and the on legend will be visible only when both the switch and circuit breaker are closed.

This mechanism consists of a rectangular frame 75 lying flat on top of the strap 12. Extending from each end of the frame are tongues 76 having fingers 77 bent around the edges of the strap to hold the frames slidably thereon. The-frame 75 has rectangular center aperture 78 for the hand lever in order that the frame may slide upon the strap, within limits, without engaging the hand lever.

The frame has the legends on and off stamped on one tongue in such position that one or the other of the legends will be visible at all times through the window 72 in the face plate. The side 80 of the frame 75 near the switch contacts is bent down to lie along the strap side plate 18 and to this part of the frame one end of a spring 82 is secured the other end being anchored to the side plate 18. This spring biases the frame 75 to show the legend on through the'window 72. The bent side of the frame is slotted adjacent the spindle 17 in order that the sliding movement of the frame may not be hindered.

Since the frame is biased to show on, I

circuit breaker. Cooperating with this slot I 84 is a tooth 85 secured on the latch bar 44 and oscillating therewith. \Vhen the circuit breaker is closed, this tooth 85 is retracted allowing the spring 82 to bias the frame to show on through the window 72, if the switch also is closed. If the switch is open, there is suflicient lost motion between the tooth 85 and the slot edges to allow the switch through mechanism as will now be described to move the frame 7 5 to show off through the window.

The bent down side 80 of the frame has an extension which cooperates with the movable switch members mounting 91 i. e. an arm of the yoke of the snap switch. This arm moves as the switch is opened and closed. As

it moves when the'switch is o ened, it pushes against the extension there y moving the frame 7 5 against the tension of spring 82 and causing the legend off to show through the window. The mounting 91 moves away from the extension 90 when the switch is closed and allows the spring 82 to act pulling the frame and causing the legend on to appear under the window.

Thus when both switch and circuit breaker are closed neither the tooth 85 nor the mounting 91 will be acting on the frame 75 and hence the frame is biased by spring 82 to show the on legend. Now if an overload occurs the circuit breaker will open causing the tooth 85 to press against the end of the slot 84 and push the frame against the tension of spring 82 to show the legend off.

To afl'ord easy access to the mechanism of my device I make one side wall 95 removable. A sheet of. insulating material which slides in slots 96 in the end walls of the casing forms this wall. When the face plate is secured in position over the casing, the wall 95 is held permanently in place.

Many changes and modifications may occur to those skilled in the art, and it will be obvious to them that many of the parts may be made either of metal or insulation, therefore I do not limit my invention to the specific modification shown.

I claim:

1. A switch device having fixed and movable contacts, a lever reciprocable to actuate said movable contacts, snap switch mechanism interposed between said movable contacts and said lever to move said movable contacts with a snap action both to circuit making and circuit breaking positions, in combination with an automatic circuit breaker normally stressed to open circuit potomatic circuit breaker normally stressed to toward open circuit position, releasable open circuit position, latch means adapted to trip said circuit breaker and break circuit through the device upon overload, said circuit breaker being, resettable by said lever.

3. A switch device having fixed and movable switch contacts, a hand lever reciprocable to actuate said movable contacts, snap.

switch mechanism interposed between said movable contacts and said lever to move said movable contacts with a snap action, a resetting finger associated with said lever, in combination with an automatic circuit breaker normally stressed to 'open circuit position, latch means adapted to trip said circuit breaker to break the circuit through thedevice upon overload, said circuit breaker being resettable by said resetting finger.

4. A switch device having fixed and movable switch contact's, a hand lever reciprocable to actuate said movable contacts, snap switch mechanism interposed between said movable contacts and said lever to move said movable contacts with a snap action, a resetting finger on said lever, in combination n :th an automatic circuit breaker adapted to break the circuit through the device upon overload, said circuit breaker comprising fixed and movable contacts, said movable circuit breaker contacts being normally stressed means holding said movable circuit breaker contacts in closed circuit position, said means cooperating with said resetting finger whereby said circuit breaker may be reset.

5. A switch device having fixed and movable switch contacts, a hand lever reciprocable to actuate said movable contacts, snap switch mechanism interposed between said movable contacts and said lever to move-said movable contacts with a snap action, a resetting finger associated with said lever, in combination with an automatic circuit breaker adapted to break the circuit through the device upon overload, said circuit breaker comprising fixed and movable contacts, a releasable latch bar cooperating with said circuit breaker contacts to hold them in closed circuit position, said resetting finger cooperating with said latch bar whereby said circuit breaker may be reset.

6. A switch device having fixed and movable switch contacts, a hand lever reciprocable to actuate said movable contacts, sna switch mechanism interposed between sai movable contacts and said lever to move said i movable contacts with a snap action, a resetting finger associated with said lever, 1n.

combination with an automatic circuit breaker adapted to break the circuit through the device upon overload, said circuit breaker comprising fixed and movable contacts a latch bar and a trigger member cooperatin to hold said circuit breaker contacts in close said movable contacts with a snap action, a

resetting finger associated with said lever, in combination with an automatic circuit breaker adapted to break the circuit through the device upon overload, said circuit breaker comprising fixed and movable contacts, a latch bar, a trigger member, a thermal elemnt cooperating with said trigger member whereby said circuit breaker contacts may be held in closed circuit position or released, said resetting finger cooperating with said latch bar to reset said circuit breaker.

8. A switch device having fixed and movable switch contacts, means to actuate said movable switch contacts, in combination with a thermally controlled circuit breaker and a single means movable to indicate the condition of the device, said means physically cooperating with said switch and circuit breaker and being actuable by both.

9. In a device of the character described, the combination of a switch mechanism with a circuit breaker mechanism, and a sin le means indicating the condition of the device said means comprising a slidable plate actuable by both the switch mechanism and circuit breaker mechanism.

10. In a device of the character described, the combination of a switch and circuit breaker in series circuit therewith, means physically associated with said switch and circuit breaker truly indicatin at all times the condition of the circuit, sai means bein movable by both said circuit breaker and said switch.

11. In a device of the character described, the combination of a switch with a circuit breaker, said switch comprising fixed and movable contacts and snap mechanism to move said movable contacts, said circuit breaker comprising fixed and movablecontacts, a latch bar moving with said movable circuit breaker contact, and indicating mechanism controlled thereby.

12. In a device of the character described, the combination of a switch with a circuit breaker, said switch comprising fixed and movable contacts and snap mechanism to move said movable contacts, said circuit breaker comprising fixed and movable contacts, a latch bar moving with said movable circuit. breaker contact, and indicating mechanism controlled thereby, said indicating mechanism being controlled also by said switch mechanism.

13. In a device of the character described, a switch, comprising fixed and movable contacts, a hand lever for actuating said movable contacts, and a yoke supporting said movable switch contacts, in combination with a circuit breaker comprising fixed and movable contacts, a latch bar moving with said movable circuit breaker contacts, and indicating mechanism actuable b said latch bar and said yoke to indicate tl ie condition of the device.

14;. In a device of the character described, a switch, comprising fixed and movable con tacts, a hand lever for actuating said movable contacts, and a yoke supporting said movable switch contacts, in combination with a circuit breaker comprising fixed and movable contacts, a latch bar moving with said movable circuit breaker contacts, and a slidable indicating plate actuable by said latch bar and yoke to show the condition of the device.

15. In a device of the character described, a face plate, a window therein, indicating means visible through said window, a switch, a circuit breaker, and means controlled by said switch and said circuit breaker to actuate said indicating means to show the condition of the device.

In testimony whereof I have signed my name to this specification.

ARVID H. NERO. 

